The present invention relates to an Ag--Cu alloy for a sliding contact as well as to a composite of a Cu or Cu alloy base material and the Ag--Cu alloy and to a compact DC motor employing as a commutator such composite.
While Ag--Cu alloys have been heretofore employed as materials for a sliding contact, the hardening of a solid solution is not sufficiently realized because the metallurgical structure is not sufficiently controlled and especially since Cu atoms are not completely solid-solubilized in an Ag-.alpha.-phase. The material for a sliding contact prepared from prior art Ag--Cu alloys is therefore softer and is subject to rapid abrasion because of its insufficient abrasion resistance at the time of sliding due to the unevenness of the metallurgical structure at the time of its manufacture. In case of a compact DC motor employing a commutator manufactured with such prior art material, abrasion is caused by the sliding with brush contact to produce abrasion powder which is responsible for making a noise.